The present invention relates to a method of and a system for transferring cardboard blanks.
At present, with particular reference to the field of packaging and/or wrapping machines, various systems for transferring cardboard blanks are known, but these systems are substantially unable to collect and supply at high speed flat cardboard blanks with large dimensions.
The object of the present invention is to eliminate the above-described disadvantage.
The invention accomplishes the object with:
a store for collection of cardboard blanks, which extends longitudinally along its own longitudinal axis, and is designed to present in the vicinity of its downstream end the cardboard blanks to be transferred;
a conveyor, which extends longitudinally along its own longitudinal axis, which is aligned with the axis of the store, wherein the upstream portion of the said conveyor is designed to receive the cardboard blanks;
a rotary collector-translator, which is designed to rotate relative to an axis perpendicular to the axes of the store and of the conveyor, and is disposed between the downstream end of the said store and the upstream portion of the said conveyor, and comprises one or a plurality of orbiting gripper units, which are designed to collect the cardboard blanks in succession from the downstream end of the store, and then to deliver them onto the upstream portion of the conveyor.
The transfer of each individual cardboard blank comprises the following operations: a)-gripping of the cardboard blank at the downstream end of the store; b)-extraction of the cardboard blank from the downstream end of the store; c)-translation of the cardboard blank towards the axis of rotation of the rotary collector-translator, whilst keeping the said cardboard blank substantially parallel relative to the successive cardboard blank, which is still disposed in the vicinity of the downstream end of the store; d)-spacing the cardboard blank which is being translated, from the successive cardboard blank, which is still disposed in the vicinity of the downstream end of the store, while keeping the said cardboard blank which is being translated substantially parallel to the successive cardboard blank, which is still disposed in the vicinity of the downstream end of the store; e)-inclining the cardboard blank which is being displaced, while moving its front portion towards and above the upstream portion of the conveyor; f)-placing at least this front portion of the cardboard blank which is being displaced, parallel to and above, and in contact with, the upstream portion of the conveyor.
Each of the orbiting gripper units comprises one or a plurality of suckers, which are controlled so as to move in respective orbital paths, which are disposed in respective planes perpendicular to the axis of rotation of the said rotary collector-translator. The upstream portion of the conveyor extends within the operative context of the orbital path of the suckers. In the execution of their orbital paths, the suckers pass adjacent to the upstream portion of the conveyor.
A rotary collector-translator is thus provided with orbiting gripper units, which are circumferentially equally spaced, and wherein the rotary collector-translator has;
an orbiting and oscillating shaft, which is supported so as to be rotated by, and between, two rotary elements, in the vicinity of their radial periphery, is oriented parallel to the said axis of rotation of the rotary collector-translator, and is designed to orbit along a circular path. One or a plurality of arms, which on the collector translator can be inclined in respective planes which are perpendicular to the axis of rotation, and have one end which is secured to the said orbiting and oscillating shaft, and the opposite end which is designed to support respective orbiting suckers. A first toothed wheel is keyed onto the said orbiting and oscillating shaft, a second toothed wheel is supported to rotate adjacent to the said first toothed wheel, by means of a pin which projects axially from one of the said rotary elements and a toothed belt is wound around the first toothed wheel and around the second toothed wheel. A lever, has a first end secured to the second toothed wheel, and an opposite, or second, end designed to support in an idle rotary manner a cam-follower roller, the cam-follower rollers of each orbiting gripper unit being designed to follow the profile of a common stationary cam.
A first advantage of the present invention is that it is possible to transfer at high speed cardboard blanks which have large dimensions, with a consequent increase in the production capacity of the corresponding packaging machines.
A further advantage of the present invention is that the said transfer at high speed takes place by means of positive translation, wherein, substantially, the cardboard blanks are always firmly grasped by the operative means, with consequent reduction of possible jamming caused by malfunctioning.
Further characteristics and advantages of the present invention will become more apparent from the following description of a preferred practical embodiment, provided here purely by way of non-limiting example, with reference to the figures in the accompanying drawing.